In some of his latest comments, Jeff Moore talks about some of the statistics that have been floating about lately about PHP 5 adoption and PHP as a "deployment platform".
PHP has been incredibly successful as a deployment platform for web applications. However, PHP as a platform is far from homogenous. With many different versions installed and the vast configurability of php.ini, there can be a great deal of variation from PHP installation to PHP installation. PHP developers often ask what should I target?
In his opinion, the statistics about usage need to be taken with a grain of salt and, with a bit of digging, some of the differences between them (expose_php anyone?) can be found. He rounds out the post with a recommendation to all developers out there - since the barrier for moving to PHP 5 is so low these days, what's stopping you?